Brain lymphoma survival usually focuses on the survival time of patients with central nervous system lymphoma. Survival time of brain lymphoma is usually related to its type, which can be divided into primary and secondary CNS lymphoma. Primary CNS lymphoma can be caused by immunodeficiency, EBV infection, etc., which is more malignant and with faster development of the disease, the average survival time can be about 6 weeks to 6 months. Besides, secondary CNS lymphoma can be caused by systemic lymphoma invading into the CNS, which is usually more difficult to treat and has a poorer prognosis, with a median survival period of about 4 months.